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6. What is the principal focus (diverging lens)?

  • Where the axis crosses the lens
  • Where rays hitting the lens parallel to the axis appear to come from
  • where rays hitting the lens parallel to the axis all seem to meet

7. What is the force that keeps things moving in a circle?

  • Earth
  • Centripetal
  • Velocity

8. What type of lens is use for magnifying glasses?

  • Convex
  • Concave

9. How can you tell something is a real image?

  • it can be seen on a TV
  • the light can produce an image on the screen
  • it can be seen with a magnifying glass

10. What is the principal focus (converging lens)?

  • where rays hitting the lens parallel to the axis all seem to meet
  • Where the axis crosses the lens
  • where the eye focuses

11. Pressure in a liquid is..

  • difficult to see
  • transmitted equally in all directions
  • hard to measure

12. What is the focal length?

  • the distance from the centre of the lens to the principal focus
  • The distance from each of the principal focuses
  • The distance from the eye to the lens

13. What type of lens is used for long sighted people?

  • Convex/converging
  • Concave/Diverging